In recent years, teleconferencing using telephone or other networks such as the Internet has become a convenient, time-saving and commonly used alternative to face-to-face meetings during which information is conveyed and/or business conducted. Such teleconferencing is often used for educational purposes and, importantly, sales presentations to potential customers. Therefore, it is important that such teleconferences be carried out in a smooth and expeditious manner.
As telecommunication techniques have developed, it has become common and found to be most economical to conduct voice communications over special telephone connection arrangements and to provide graphical information through network-connected computers such as so-called personal computers, laptop computers, palm-top device, smart phones and the like which are networked through the Internet or private networks that may or may not include wireless links. While analog or digital telephony is capable of substantially instantaneous communications, the same is not true for information transmitted digitally over networks, particularly for graphic or text information, where significant delay or latency can occur.
Such delay or latency, or at least a major portion thereof, is generally due to the manner in which packetized information is handled by the network to achieve high efficiency and degree of utilization of the network in order to accommodate a maximized amount of simultaneously transmitted information. To achieve high efficiency and degree of network utilization, the information to be transmitted is divided into packets and each packet is divided into a header portion and a payload portion that are associated with each other throughout the communication. The header portion contains information in regard to the intended destination, a message identifier and a packet number. The payload portion contains a respective portion of the information to be transmitted. With such header and payload information contained in each packet, it becomes irrelevant to the transmission whether the individual packets are transmitted over the same or different interconnection routes or whether or not the packets are received in order. The packet is simply stored, as received, and the information re-assembled incrementally and in the order specified by the packet number for a particular message until the message is complete. Therefore, the delay or latency which can occur is at least the sum of the longest transmission time of any packet in the message and the time for the message to be re-assembled and read out of the memory in which it is collected and re-assembled. For image information, a portion of the delay may also be due to the time and processing required to render the image using the hardware and software available. Thus the total delay or latency can range from a fraction of a second to several tens of minutes.
The delay or latency is often substantially transparent to users of the network when there is no real-time indication to the intended recipient of the transmission of the message. However, when the message is accompanied by a parallel substantially instantaneous communication by telephony or the like, the recipient generally has a frame of reference for the transmission and a degree of synchronization of the two communication links is required. Such synchronization is usually achieved by simply waiting until the receipt of graphic or text message is acknowledged by all participants to resume the voice link communication. The only alternative is to proceed with a presentation even though the associated graphic information may not be available to all participants, possibly for an extended period of time. Further, the need to transmit and process acknowledgments may delay the presentation beyond the time when graphic information has become available to all participants. Such unavoidable interruptions and delays clearly reduce the quality and effectiveness of the teleconference, unnecessarily increase the teleconference duration and have a strong adverse impact on the effect made by the presenter, particularly for purposes of sales.